Hi All,
I found this interesting. I had planned to upgrade the v-belt on my table saw
to eliminate some vibration. Searching around I came across this article.
Vibration Free Link Belts
Vibration Free Link Belts
Copyright © 2004 by
Jim Wilson
(Click images to enlarge)
PowerTwist (red) and Accu-Link (green)
What are they?
Vibration can be more than a mere annoyance for many tools. It can reduce
accuracy, roughen cut surfaces, and increase noise levels. "Vibration free" link
belts are formed from interlocking segments that twist together. Their link
structure can dampen vibration from other sources, such as unbalanced pulleys.
They are more durable than standard v-belts and they are easier to install and
remove.
When to use them
I have the twist-lock link belts on much of my machinery, including my cabinet
saw, which takes three matched belts. Everything works just fine; my cabinet
saw easily passes the "nickel test."
Nonetheless, I have found by experimentation that the link belts are no better
than cogged v-belts in some applications, and no better than top quality
ordinary v-belts in others. Cogged belts share many of the advantages of link
belts: excellent vibration dampening characteristics, reduced slippage, higher
energy efficiency, longer life, and resistance to taking a set.
Additionally, there is no waste, as occurs with a link belt when there is a
leftover, unused portion, and which drives the already high cost of link belts
up even more. On the down side, cogged belts are not adjustable and when they
break (exceedingly rare) the entire belt is lost, as opposed to one or a
few links. Personally, I'm willing to give up these latter two advantages in
exchange for the cost savings when the link belts don't perform noticeably
better on a given machine.
The unchallenged advantages of the link belts are (1) the ease of replacement,
especially in cases where machinery must ordinarily be disassembled for it,
and (2) the ease of maintaining spare inventory.
While both the link belts and the cogged v-belts dampen vibration, the link
belts are a little better with lower frequency vibrations such as are caused
by pulley or load imbalances. However, both types of belt also introduce some
higher frequency noise owing to their "teeth." In this respect the link belts
are noticeably worse (louder in the higher frequencies), and they also squeak a
bit from the links rubbing against one another and the pulleys or sheaves.
Because of this, a machine may sound quieter or louder with the link belt than
with a cogged or regular v-belt. On all my machines that run them, save one,
the link belts are as quiet or quieter than regular or cogged v-belts. The
oddball is an old Delta 14" bandsaw whose sheet metal stand apparently
oscillates
in harmony with the higher pitch of the link belt links. That saw runs about 3
dBA quieter with a cogged v-belt and 2 dBA quieter with a regular v-belt.
On a very smooth running machine, like a top-quality metalworking lathe or
mill, a premium classic v-belt runs the quietest and with the least vibration.
Ultimately, it's a price/performance decision. Here is some slightly dated
pricing information I collected from MSC (
www.mscdirect.com
), one of my favorite industrial suppliers. Prices for 36", 48", and 60"
classic v-belts are $6.80, $8.16, and $9.35, respectively. Cogged belts in the
same sizes run $8.43, $10.14, and $11.47. Assuming no waste, the same link
belts would cost about $12, $16, and $20 each at Harbor Freight pricing.
Something
to think about.
Where to get them
There are at least two brands currently on the market:
PowerTwist
belts, manufactured by Fenner Drives, are red.
Accu-Link
belts, from Jason Industrial, are green.
Links - side view
Harbor Freight
has the best price ($20 for 5 feet) that I have seen, and I have searched high
and low. If you find a better price, let me know, and I will update this
page.
I believe
Fenner Drives
invented this style of link belt. I have been using the PowerTwist brand for
years, and am very happy with them. I currently have them installed on my
vertical mill, metal lathe, wood lathe, and metal bandsaw.
The best price I have seen recently on the PowerTwist brand is $24 for 5 feet
at
McMaster-Carr
. Double check with them before you order, though, to be sure they are still
shipping the PowerTwist brand. They often do not publish brand names, and have
been known to substitute.
In October 2001, I needed belts for some new additions to my wood shop. I
ordered from Harbor Freight and received the Accu-Links. I had previously gotten
the PowerTwist brand from them. The Accu-Links are installed on a Rockwell 10"
Unisaw, 14" bandsaw, and shaper, an 8" jointer, and a 20" drill press.
Which brand is better?
Links - outside view
So far, there is no noticeable difference in performance between the two
brands, although the PowerTwist appear to be slightly better quality all around,
perhaps by as much as the price difference.
Both brands are made of a urethane elastomer reinforced with woven polyester
fabric. The Accu-Link urethane does not appear as though it will be as durable.
Accu-Link flaking
Twisting the links apart and together causes little bits to flake off. They
flakes have a waxy consistency. The amount of flaking is small, and may well
be negligible over the life of the belt. I mention it only because I have never
noticed it with the PowerTwist brand. Flakes are shed during use also,
as can be seen in this photo of my drill press. The flakes are dusty and
usually dispersed by the turbulent air around the moving belt, but they do stick
to nearby oily areas.
Links - side view
Overall, the PowerTwist links are neater. They are cut more cleanly. The
surface of the belt material is smoother. The weave looks tighter.
Links - inside view
The PowerTwist also has a smaller size increment, owing to a slightly smaller
link size. Each PowerTwist link adds 3/4" to the belt length. The Accu-Links
are 7/8". Both of these measurements are for new belts. They do tend to stretch
some during the first few hours of use, so the true long-term increment
will be a bit higher.
The 1/2" Accu-Links are a little wider than the 1/2" PowerTwist. I thought they
seemed a tad too wide for the Unisaw pulleys, and I was concerned about
them rubbing on each other. So far, though, the fear has proved unfounded. The
saw runs fine, and there's no evidence of excessive wear, etc. By the way,
some users have reported that using link belts on their cabinet saws helps to
reduce startup "thump," which is apparently caused by high motor torque.
My own Unisaw has never thumped, but then again, I've never used classic
v-belts on it.
The differences may be inconsequential with respect to function, performance,
and durability. There's no way to tell in the short term. Since they were
installed, though, the green belts have turned my machinery as well as the red
ones.
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